Enzyme catalysis is the increase in the rate of a process by a biological molecule, an "enzyme". Most enzymes are proteins, and most such processes are chemical reactions. Within the enzyme, generally catalysis occurs at a localized site, called the active site.
Most enzymes are made predominantly of proteins, either a single protein chain or many such chains in a multi-subunit complex. Enzymes often also incorporate non-protein components, such as metal ions or specialized organic molecules known as cofactor (e.g. adenosine triphosphate). Many cofactors are vitamins, and their role as vitamins is directly linked to their use in the catalysis of biological process within metabolism. Catalysis of biochemical reactions in the cell is vital since many but not all metabolically essential reactions have very low rates when uncatalysed. One driver of protein evolution is the optimization of such catalytic activities, although only the most crucial enzymes operate near catalytic efficiency limits, and many enzymes are far from optimal. Important factors in enzyme catalysis include general acid and base catalysis, orbital steering, entropic restriction, orientation effects (i.e. lock and key catalysis), as well as motional effects involving protein dynamics[1]
Mechanisms of enzyme catalysis vary, but are all similar in principle to other types of chemical catalysis in that the crucial factor is a reduction of energy barrier(s) separating the reactants (or substrates) from the products. The reduction of activation energy (Ea) increases the fraction of reactant molecules that can overcome this barrier and form the product. An important principle is that since they only reduce energy barriers between products and reactants, enzymes always catalyze reactions in both directions, and cannot drive a reaction forward or affect the equilibrium position – only the speed with which is it achieved. As with other catalysts, the enzyme is not consumed or changed by the reaction (as a substrate is) but is recycled such that a single enzyme performs many rounds of catalysis.
Enzymes are often highly specific and act on only certain substrates. Some enzymes are absolutely specific meaning that they act on only one substrate, while others show group specificity and can act on similar but not identical chemical groups such as the peptide bond in different molecules. Many enzymes have stereochemical specificity and act on one stereoisomer but not another.[2]
^Kamerlin SC, Warshel A (May 2010). "At the dawn of the 21st century: Is dynamics the missing link for understanding enzyme catalysis?". Proteins. 78 (6): 1339–1375. doi:10.1002/prot.22654. PMC 2841229. PMID 20099310.
^Laidler KJ (1978). Physical Chemistry with Biological Applications. Benjamin/Cummings. p. 427. ISBN 978-0-8053-5680-9.
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the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the cell need enzymecatalysis in order...
components are not in the same phase. Enzymes and other biocatalysts are often considered as a third category. Catalysis is ubiquitous in chemical industry...
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In chemistry, homogeneous catalysis is catalysis where the catalyst is in same phase as reactants, principally by a soluble catalyst a in solution. In...
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artificial enzyme is a synthetic organic molecule or ion that recreates one or more functions of an enzyme. It seeks to deliver catalysis at rates and...
processes that have been identified as influenced by quantum effects: enzymecatalysis, sensory processes, energy transference, and information encoding....
of the 21st century: Is dynamics the missing link for understanding enzymecatalysis?". Proteins: Structure, Function, and Bioinformatics. 78 (6): 1339–75...
other kinds of substance besides enzymes (for example, vitamins and hormones). Turnover number Enzyme assay Enzymecatalysis Nomenclature Committee of the...
second half still covalently bound to the enzyme as an acyl-enzyme intermediate. Although general-acid catalysis for breakdown of the First and Second tetrahedral...
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of the product. This covalent acyl-enzyme intermediate is then hydrolyzed by activated water to complete catalysis by releasing the second half of the...
quantifying the catalytic activity of enzymes (that is, measuring the enzymatic activity level in enzymecatalysis) and other catalysts. The unit 'katal'...
the product of hydrolysis and leaving the enzyme unchanged. This type of covalent mechanism for enzymecatalysis was first proposed by Koshland. More recently...
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ISBN 978-0-7167-4955-4. Simón, Luis; Goodman, Jonathan M. (March 19, 2010). "EnzymeCatalysis by Hydrogen Bonds: The Balance between Transition State Binding and...
S2CID 72434859. Jencks, W. P. (1975). "Binding energy, specificity and enzymecatalysis: the Circe effect". Adv. Enzymol. Relat. Areas Biochem. 43: 219–410...
catalytic constants for the different forms of this enzyme range between 104 s−1 and 106 s−1. Catalysis Roskoski, Robert (2015). "Michaelis-Menten Kinetics"...
Society in his late 30s in 1983 for his work illuminating enzymiccatalysis and how enzymes attain high fidelity in the translation of the genetic code...
magnetite, and vugs or stained quartz. Oxidation may occur through enzymecatalysis by iron bacteria. It is not clear whether the magnetite precipitates...
to functionally relevant phenomena such as allosteric signaling and enzymecatalysis. The study of protein dynamics is most directly concerned with the...
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